advantages of rifle length system?

[TheJawn]

What are the pros and cons to 12-inchers? Off the top of my head the advantages are muzzle velocity and recoil impulse. Does it generally wear on parts less than shorter systems? If that's the case is it worth the extra weight up front?

Why would someone choose a 20 inch rifle over a 16 inch mid?

[a0cake]

What are the pros and cons to 12-inchers? Off the top of my head the advantages are muzzle velocity and recoil impulse. Does it generally wear on parts less than shorter systems? If that's the case is it worth the extra weight up front?

Why would someone choose a 20 inch rifle over a 16 inch mid?

I'm guessing by 12'' you mean the 13.2'' rifle-gas system. The only reason NOT to go with a rifle as opposed to a mid-length or carbine is size and weight. If weight is not a concern, you won't be getting in and out of vehicles, clearing rooms, etc, then absolutely a rifle length system is the way to go. The rifle-gas system is the softest shooting, the most reliable, and has the greatest longevity due to decreased wear. Another often overlooked advantage is increased sight-radius if you're using irons.

Now, it's a common fallacy that longer barrels are inherently "more accurate" than shorter barrels. In fact, at 100-200M the opposite is often true due to the increased rigidity of a short barrel. But, as range increases, velocity becomes more important. Errors in range estimation and the effects of wind are greatly mitigated by the higher velocity you get out of a longer barrel. This translates to increased hit probability at long range. This isn't to say that short barrels (even SBR's) aren't capable of long range accuracy, just that they're not ideal.

So, it comes down to size and weight. If, for your purposes, these considerations are important, then consider a carbine or a midlength. If not, definitely go with the rifle. Ultimately, you'll have to weigh the pros and cons and decide for your own purposes.

[TheJawn]

That was a great answer, and thank you!